This trial is designed to test the safety, immunogenicity, and clinical activity of autologous peripheral blood dendritic cells (DCs) pulsed with tumor-derived idiotype protein in patients with low-grade B-cell lymphoma. The long-term goal of this study is to develop a vaccine therapy which will induce a clinically effective immune response. The vaccine is produced on a custom basis from each patient's tumor cells and peripheral blood. In a pilot study, cellular immune responses and tumor regressions were observed.